Ecogenomics of small Phytoplankton & large Virus Interactions in response to changing salinity and phosphate concentrations

• Applicant: Professorin Dr. Elisa Schaum, Ph.D.
• Subject Area: Microbial Ecology and Applied Microbiology ; Ecology and Biodiversity of Plants and Ecosystems
• Term: since 2021
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 490839374

The overarching objective of ELVIRA is to gain fundamental knowledge into the genome x phenotype x environment interactions and its consequences on microalgae-virus population dynamics. To reach this aim, ELVIRA will assess the effect of environmental changes on phytoplankton-virus interactions. While the effect of temperature on phytoplankton-virus community dynamics has been scrutinised in the last decade in many cosmopolitan marine phytoplankton species to show that temperature variations indeed affect host-virus interactions both qualitatively and quantitatively, there is less knowledge about the effects of other environmental parameters brought by global change. For example, ocean stratification increases with temperature, and as a consequence, surface waters can become nutrient deplete. Temperature can further affect salinity through increased evaporation or changed in rainfall patterns. Both nutrient availability and salinity are important players in infection dynamics. To fill this gap, we will take advantage of the contrasting environmental characteristics of surface waters of the Baltic, North and Mediterranean Seas where salinity and nutrients (in particular phosphate) differ both between and within regions. Wewill investigate how salinity and phosphate availability affect phytoplankton- virusinteractions, from the molecular changes involved in altering phenotypes to the populationdynamics. The regions we chose also allow us to investigate the above questions on evolutionary timescales through a space-for-time substitution approach. Using this approach, we can then determine the evolutionary potential of the hosts and their viruses, to be better able to predict relevant dynamics and traits in the environments we expect to find in a changing world. We will use an ecological relevant model, the Ostreococcus-prasinovirus system, which is amenable to experimentation and has been shown to be prevalent in both the North, the Baltic and the Mediterranean seas.

• DFG Programme: Research Grants
• International Connection: France
• Co-Investigator: Dr. Luisa Listmann
• Cooperation Partner: Professorin Gwenael Piganeau